Liquid crystal displays (LCDs) have been used in various electronic devices. A Vertically Aligned Mode (VA mode) LCD is developed to provide a wider viewing range. When a user looks at an LCD in the VA mode from an oblique direction, the skin color of Asian people (light orange or pink) appears bluish or whitish. Such a phenomenon is called color wash out.
A Multi-Domain Vertically Aligned Mode (MVA mode) LCD was developed by Fujitsu in 1997 to provide a wider viewing range. In the MVA mode, a 160 degree view angle and a high response speed was achieved. However, when a user looks at this LCD from an oblique direction, the skin color of Asian people (light orange or pink) appears bluish or whitish. Such a phenomenon is called color shift.
The transmittance-voltage (T-V) characteristic of the MVA mode liquid crystal display is shown in FIG. 1. The vertical axis is the transmittance rate. The horizontal axis is the applied voltage. When the applied voltage is increased, the transmittance rate curve 101 in the normal direction also increases. The transmittance changes monotonically as the applied voltage increases. In the oblique direction, the transmittance rate curve is the curve 102. However, in the region 100, when the applied voltage is increased, the transmittance rate curve 102 is not increased. That is the reason the color shifts.
A method is provided to improve the foregoing problem. According to the method, a pixel unit is divided into two sub pixels. The two sub pixels may generate two different T-V characteristics. By combining the two different T-V characteristics, a monotonic T-V characteristic can be realized. The line 201 in FIG. 2 shows the T-V characteristic of a sub-pixel. The line 202 in FIG. 2 shows the T-V characteristic of another sub-pixel. By combining the two different T-V characteristics of line 201 and line 202, a monotonic T-V characteristic can be realized, as shown by the line 203 in FIG. 2.
Therefore, a pixel unit is required to resolve the foregoing problems.